In the past it has been taught in specific applications that article-supporting carriers may be moved along a desired path and may be switched in relative position between side-by-side and end-to-end relationships.
One such application involves the moving of carriers in an end-to-end relationship enroute to and from an oven which processes articles on the carriers. As the carriers approach the oven, the carriers are positioned in side-by-side series to pass through the oven in a closely packed arrangement. The switching of relative positioning between adjacent carriers is effectuated by disposing each carrier between two trolleys and running the trolleys either (a) along a monorail to achieve an end-to-end orientation for a carrier or (b) along two parallel tracks to achieve a sideways orientation for a carrier. This arrangement, shown in U.S. Pat. No. 3,195,473, provides that each carrier at all times extend lengthwise between the two trolleys.
While addressing the questions of grouping carriers together for processing in an oven, U.S. Pat. No. 3,195,473 does not consider the problem of processing an article which may be significantly longer than the oven is wide. Similarly, the patent does not suggest how other processing devices of limited width might process elongated articles which extend beyond the area covered by such other devices.
This problem is particularly significant where an irradiation beam of a given beam scan width B is to irradiate an article or articles extending across a length L on a carrier, where L is significantly larger than B.
In environments where open floor space is sought, it is desirable to suspend the carriers from overhead tracks. In suspending carriers to be irradiated by a beam, a further problem arises regarding how to suspend the carriers without interfering with the beam. In applying the teachings of the past, elongated articles might be oriented in a cross-wise or lateral orientation as they are conveyed along the two tracks, the articles extending beyond the scanned area of the beam, resulting in non-uniform irradiation of the articles.
Similarly, where small articles dispersed on an elongated carrier which has a length L greater than the scan width B of the beam, conveying the carrier cross-wise through the beam, i.e. relatively parallel with the beam scan width, could result in articles or portions thereof supported along the edges of the carrier to be unexposed or less exposed to the radiation.
The prior technology in general has not confronted the problem of conveying articles which cover a length longer than the scan width of an irradiation beam through such a beam. Moreover, the prior technology does not confront this problem in the context of a conveyor system intended to make best use of processing plant space.